It is well established practice to convert power available at one voltage into power at a higher or lower voltage. However, as is well known, peak voltage spikes sometimes in excess of 10 times the originating nominal supply voltage, can occur for very short durations (of the order of a few microseconds). Such spikes can be (and usually are) removed by employing a voltage dependent resistor or the like across the power supply input from the originating supply. However, such devices are not well suited to remove longer duration spikes of lesser magnitude typically 2-3 times the nominal supply voltage.
It is an object of the present invention to provide a protection circuit for use in connection with a converter of the type described, which will protect the converter render the converter output largely insensitive to these longer duration spikes.